design-patterns-python/strategy_pattern.py at main · Artemooon/design-patterns-python · GitHub

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from abc import ABC, abstractmethod


class WeaponBehavior(ABC):

    @abstractmethod
    def use_weapon(self):
        raise NotImplementedError


class Character(ABC):
    weapon: WeaponBehavior = None

    def set_weapon(self, new_weapon: WeaponBehavior):
        self.weapon = new_weapon

    @abstractmethod
    def fight(self):
        pass

    def display_character_name(self):
        print("This is base character")


class King(Character):

    def __init__(self):
        self.weapon = KnifeBehavior()

    def fight(self):
        self.weapon.use_weapon()


class Queen(Character):

    def __init__(self):
        self.weapon = BowAndArrowBehavior()

    def fight(self):
        self.weapon.use_weapon()


class KnifeBehavior(WeaponBehavior):

    def use_weapon(self):
        print("I use knife")


class BowAndArrowBehavior(WeaponBehavior):

    def use_weapon(self):
        print("I use bow and arrow")


king = King()
queen = Queen()

king.fight()
queen.fight()
king.set_weapon(BowAndArrowBehavior())
king.fight()


class Strategy(ABC):

    @abstractmethod
    def do_algorithm(self, data: list[str]):
        raise NotImplementedError


class Context:

    def __init__(self, strategy: Strategy):
        self._strategy = strategy

    @property
    def strategy(self):
        return self._strategy

    @strategy.setter
    def strategy(self, strategy: Strategy):
        self._strategy = strategy

    def do_some_business_logic(self):
        text_data = ["a", "b", "c"]
        result = self.strategy.do_algorithm(text_data)
        print(",".join(result))

class ConcreateStrategyA(Strategy):

    def do_algorithm(self, data: list[str]):
        return sorted(data)

class ConcreteStrategyB(Strategy):

    def do_algorithm(self, data: list[str]):
        return reversed(data)


strategy_a = ConcreateStrategyA()
strategy_b = ConcreteStrategyB()

context = Context(strategy_a)

context.do_some_business_logic()

context.strategy = strategy_b

context.do_some_business_logic()